Tissue engineering—an ability to improve or replace biological function through repair or replacement of tissues—enables creation of artificial, fully functional tissues and organs. Expertise from fields such as photo/imprint-lithography (physics), molecular materials (chemistry), process engineering (chemical engineering), simulation and modeling (computer science), mechanical surface modification (mechanical engineering), growth factor control (biochemistry), cell differentiation (cell biology), and more, contribute to viable, scalable industrial solutions.
Success of tissue regeneration depends on an ability to generate reliable, fully integrated, complex, three-dimensional and controlled porous structures called scaffolds of an exact shape and size for a replacement of body parts. Scaffolds are used to enable creation of tissue and/or organ substitutes, for example. Tissue or organ damage, loss, or failure, are frequent and devastating problems faced by the health system (due to trauma, infectious disease, vascular disease, inherited disease, age related disease, congential anomalies, tumor removal, and complete organ failure, for example), and therefore, several approaches are used to develop viable tissue substitutes for tissue/organ reconstruction, regeneration of damaged tissues and organs, artificial organ/tissue production, and fabrication of living tissue constructs.
Tissue engineering focuses on creating functional tissue using cells seeded onto the three-dimensional (3-D) porous scaffolds. Porous scaffolds provide a 3-D template for cell attachment and growth leading to tissue formation. An internal structure of the scaffold may have channels and interconnected pores in suitable size ranges to help cell attachment, cell proliferation, tissue regeneration, and nutrient flow. An external size and shape of the scaffold may also confirm to a replacement for body part, specific to a subject, for biological and structural acceptability.
Utilization of computer-aided technologies in tissue engineering has enabled integration of advances in biology, biomedical engineering, information technology, and manufacturing technologies. For example, three-dimensional (3-D) printing, fused deposition, stereolithography, selective laser sintering, direct material deposition, or types of layered manufacturing (LM) (also known as rapid prototyping (RP)) are examples of solid free form (SFF) techniques that may be useful for automatic construction of physical objects. In brief, SFF techniques take virtual designs as computer aided design (CAD) models, transform the designs into virtual cross sections, and then enable creation of each cross section in physical space using appropriate materials and processing one after the next until a physical model is completed.
An LM machine may deposit materials in different densities during construction of scaffolds. This can be significant in tissue engineering applications that require material performances to vary with locations in the scaffold, for example, gradients in scaffold pore sizes may be recommended for formation of multiple tissues and tissue interfaces.